This invention relates generally to a traction elevator system, and specifically to an apparatus for protecting maintenance personnel working on the roof of an elevator car.
As is well known in the art, much of the maintenance work on elevators is conducted upon the roof of the elevator car. To this end, an inspection box is mounted upon the roof of the car which has controls allowing a maintenance worker stationed upon the car roof to operate the elevator. More and more traction elevator systems are being built in which most of the mechanical components that were traditionally housed in the machine room are now being located in the hoistway. The top of the hoistway is closed by a ceiling that leaves little headroom between the elevator car roof and the ceiling when the car is stationed at the top floor landing. Accordingly, a maintenance worker located on the roof of the car can run the car extremely close to the top of the hoistway using the inspection box controls. Accordingly, a maintenance worker on the roof of the car may become entrapped between the car roof and the structure located in the top section of the hoistway.
It is therefore an object of the present invention to improve elevator systems.
It is a further object of the present invention to improve the safety of elevators.
A still further object of the present invention is to maintain adequate overhead space for a worker while he or she is situated upon the rooftop of an elevator car.
A preferred feature of the invention is to disable the up function of the elevator""s inspection box control circuitry until such time as preventative measures have been carried out to prevent a worker on top of the elevator car from becoming entrapped between the car and the structure located in the top of the hoistway.
These and other objects and features of the present invention are attained in an embodiment in which an elevator system that includes a drive mechanism that is arranged to disengage at a predetermined load resistance. A brace is mounted to the elevator car and preferably extends above the car. The brace is capable of withstanding a compressive load that is higher than the disengagement load of the drive mechanism whereupon the drive mechanism will disengage in the event an upwardly moving car raises the brace into contact with an overhead structure of the hoistway.